Update brings broad refresh of hardware support and improved quality, combined with new features and enhancements in areas such as virtualization, desktop, networking, storage & clustering and security
Powertop is Linux tool to find out what is using power on a laptop. This program only works on Intel based laptops. It is very good software to extend Laptop battery life time. I’ve tested this software with following Intel based laptops:
=> My Sony VAIO Laptop
=> My Dell 6400 Laptop
=> My office HP / Compaq Laptop
From the project page:
Computer programs can make your computer use more power. PowerTOP is a Linux tool that helps you find those programs that are misbehaving while your computer is idle.
PowerTOP combines various sources of information from the kernel into one convenient screen so that you can see how well your system is doing at saving power, and which components are the biggest problems.
PowerTOP has these four basic goals:
=> Show how well your system is using the various hardware power-saving features
=> Show you the culprit software components that are preventing optimal usage of your hardware power savings
=> Help Linux developers test their application and achieve optimal behavior
=> Provide you with tuning suggestions to achieve low power consumption
Quick PowerTOP installation
Type the following commands:
$ sudo apt-get install powertop
$ sudo powetop
(Fig. 01: PowerTop in Action [ Image Credit Intel Corp / Powertop Project] )
=> Visit official project home page to grab PowerTOP software.
This is a reader contributed article.
These days almost all server / laptop / desktop system has a gigabit Ethernet card (NIC) pre installed. Most servers are directly connected to internet using 100Mbps connections. You can save real power on your Linux server or desktop by operating at 100Mbps Ethernet speed. For example 1 gigabit link is going to consume more power than the power used at 100Mbps speed. Also note that not all systems actually use gigabit speed. For example my desktop system only used for browsing or chatting purpose or Linux web server used to display just static web pages. Now just calculate power consumption for 100 servers or 1000 desktop systems. Bottom line use Gigabit Ethernet speeds only when needed. Did you know – you can save 2 watts or more per Linux/UNIX/Windows server/desktop by just setting a correct speed :)
See current Ethernet card speed
Use ethtool comment to display current speed:
ethtool eth0 | grep -i speed
Set new speed and save power
Following command will set card speed to 100Mbps:
ethtool -s eth0 autoneg off speed 100
=> For more information see ethtool command and network interface speed, duplex . auto negotiate settings on Linux
About the author: Rocky Jr., is an engineer with VSNL – a leading ISP / global telecom company in India and a good friend of nixCraft.